1. Technical Field
The present invention relates in general to the support and alignment of drill bits on drill motors and, in particular, to an improved system, method, and apparatus for the alignment of drill bits with nosepieces on ergonomic drill motors.
2. Description of the Related Art
In the manufacturing industry it is very common to form holes in workpieces to facilitate assembly of products. Holes are typically formed by using drilling equipment, such as hand-held drill motors, which are equipped with drill bits that are appropriate for the job. In some applications, a template or guide plate is used to assist drill operators in precisely locating the various positions of the holes to be drilled in the workpiece. For example, a guide plate may be complementary in shape and contoured to the workpiece to be drilled. A guide plate can have hundreds of alignment holes for the drill operator to use or “go by” to form drill holes in the workpiece. With the guide plate positioned directly adjacent or mounted to the workpiece, the drill operator pushes the rotating drill bit through each pre-formed hole in the guide plate to form the holes in the workpiece in their proper locations.
This process is somewhat prone to operator error. First, the drill bits are not always axially aligned at a proper angle of insertion (i.e., perpendicular to the surface of the workpiece) as the holes are formed. This error can lead to off-axis cylindrical holes being formed, and holes that are over bored in diameter as the drill operator tries to manually maintain axial alignment. Second, the depth of drill bit insertion can be improperly varied by drilling a hole that is too deep or too shallow in the workpiece, which can cause damage to underlying structure or render the hole inadequate for its intended purpose. Each of these errors can require extensive rework operations to repair the damage and increase waste.
In the prior art, drill bit alignment or “Sheridan” equipment is well known for facilitating more accurate hole drilling on large drilling equipment. Sheridan equipment attaches to the end of large drill motors to help maintain axial alignment of the drill bits and limit the depth of drill bit insertion. Other types of drill attachments are also known. See, e.g., U.S. Pat. Nos. 1,665,173; 1,699,870; 2,376,432; 3,776,647; and 5,564,717. Unfortunately, none of these prior art designs are adjustable and have only a limited range of operation.
Moreover, Sheridan-type equipment is completely incompatible with modern ergonomic drilling equipment, which is much smaller and far more ergonomically efficient than any prior art designs. Furthermore, equipment manufacturers have been unable to overcome the alignment and depth penetration problems that are common to the industry. Drill operators have attempted to hold an ergonomic drill in one hand and a Sheridan-type tool in their other hand in an attempt to facilitate alignment and depth control of their drill bits. However, the holes drilled by this manually-intensive process are inconsistent at best and wear out drill bits at a rapid rate. Thus, it has been a long felt need in the industry to provide ergonomic drilling equipment with drill bit alignment and depth control of the holes formed in workpieces.